github/workflows: fix preview url

.github/workflows/user_project_ci.yml

diff --git a/.github/workflows/user_project_ci.yml b/.github/workflows/user_project_ci.yml
index c7a1361..150a213 100644
--- a/.github/workflows/user_project_ci.yml
+++ b/.github/workflows/user_project_ci.yml
@@ -306,7 +306,7 @@
       uses: actions/cache@v3
       with:
         path: |
-          tiny_user_project_synth.png
+          tiny_user_project_synth.svg
           tiny_user_project_layout.png
         key: ${{ runner.os }}-img-${{ github.run_id }}
     - name: setup pages